The present invention relates generally to a degassing device for biological fluids, sometimes referred to as a bubble trap. Bubble traps have been known and used for many years in the medical industry. Particularly, bubble traps are commonly used in the process of transmitting body fluids such as blood during various medical procedures such as transfusion.
During the process of a transfusion, it is possible to inadvertently introduce gaseous bubbles into the fluid as it passes through the circuit. If these bubbles are not removed, when the fluid is introduced into the blood stream, gaseous emboli may be created. Such emboli may become attached to, and occlude, the blood vessels. When this occurs, a common result is the development of dangerous infarcts. As additional material is collected by and adheres to the emboli, thrombosis may result.
Prior art bubble traps have attempted to avoid the transmission of gas bubbles into the blood stream by directing the transfused fluid along a wire-like surface designed to attract bubbles, and then into a settling basin wherein bubbles may rise out of the standing fluids. The degassed fluid is then transmitted from the bubble trap and may be infused into the blood stream.
A significant problem related to the process of removing gas bubbles through settling is the extended time period necessary to allow those bubbles to rise to the surface of the settling fluid. This problem is aggravated by the inability of smaller bubbles to rapidly rise to the surface due to their small density difference with respect to the surrounding fluid. Hence, it is difficult to ensure that all bubbles are removed with use of the bubble traps in direct body-to-body transfusion, or in cardiopulmonary bypass circuits. This is true since the flow of blood into the body must approximately equal the flow out of the body, and thus settling times are restricted and can be controlled only by varying the size of the settling container used in the bubble trap.
These problems are substantially circumvented through the use of the bubble trap of the present invention.